Siemens S5-135U/155U - Manual (Page 67)

4-1
System Manual
C79000-G8576-C199-06
Central Controllers and Expansion Units
Power Supply Units
The S5-135U/155U programmable controller comprises a central controller
(CC) and, depending on the configuration, one or more expansion units
(EUs). Expansion units are connected when there are unsufficient central
controller slots, or when you wish to position I/O modules as closely to the
process as possible (see also Chapter 2).
With the central controllers and some expansion units, the modules are
directly powered and cooled via the integrated power supply plug-in module.
With all other expansion units, power is supplied via the IMs from the CC
(see also Chapter 7).
Section Description Page
4.1 S5-135U/155U Central Controller 4-2
4.2 Expansion Units 4-15
4.3 Power Supply Units 4-19
4.4 6ES5 955-3NA12 Power Supply Unit 4-57
4.5 Fan Submodules 4-70
Chapter
Overview
4